Epson Stylus Photo R290, Service Manual, Page: 24 / 125

EPSON Stylus Photo R280/R285/R290 Revision B
Chapter 2 Operating Principles 2.2 Electrical Circuit Operating Principles 24
2.2 Electrical Circuit Operating Principles
The electric circuits of the Stylus Photo R280/R285/R290 consist of the following
boards.
2.2.1 Main Features
The circuits support multi-common printing method that achieves high-speed printing
reducing the number of carriage movements.
† Features of C691Main Board
„ An EEPROM and a reset circuit are mounted individually to reduce the cost.
This is achieved by removing a complex RTC circuit that is mounted on the
previous model (R260/R265/R270/R360/R380/R390). Stylus Photo R280/
R285/R290 do not need the complex RTC circuit because a backup timer is
not required for them.
† Operations to reduce power consumption
The printer carries out the following operations to go into sleep mode.
„ Decreases the power voltage.
„ Shuts off photoelectric current of photo interrupter sensors.
„ Stops the motor drive circuit.
„ Stops some part of the clock in the ASIC.
„ De-energizes the motors.
„ Makes the head drive circuit go into standby state.
2.2.2 Components of Control Boards
Table 2-4. Main Boards & Model Numbers
Board Name R280/R285/R290
Main Board C691MAIN
Power Supply Board
C691PSB
Panel Board C691PNL
Table 2-5. Components of Control Boards
Board Name Incorporated Components
Main
Board
System
† Logic circuit
(SOC incorporated in the CPU core, Flash ROM (4 Mbit) x 1, SDRAM x 1,
Local SDRAM controller, Local SDRAM (64 Mbit)
† SSCG circuit
† Panel I/F
† Regulator
† Power saver
† Oscillator circuit
† Power control circuit (PSC/ESAVE)
† Reset circuit
† USB interface
† EEPROM
Printer
† Motor drive circuit (PF, CR)
† Printhead drive circuit
† CSIC/IF
† Sensor circuits
Panel Board
† Power switch read-in circuit
† LED driving circuit